1. Field of the Invention
The present invention relates to an endoscope apparatus for three dimensional measurement, for irradiating a measuring light to a subject to measure three dimensional information of a subject on the basis of an image-pickup signal produced by image pickup means.
2. Description of the Related Art Statement
It has conventionally been known that, in a plurality of images produced by a plurality of optical systems each having a parallax, points corresponding to the same or identical points on a subject are detected and it is determined to how much the points are shifted from each other, whereby a distance to the subject can be computed on the basis of the principle of triangulation.
In a case where points corresponding to the same point on a subject are specified, an observer has conventionally seen an image to execute judgment and has used a pointing unit, such as a light pen or the like, to execute indication. On the other hand, a method has been proposed in Japanese Patent Laid-Open No. SHO 59-187310 in which a scanning spot light is projected on the subject, and a point on each of images corresponding to the same point on the subject is detected without indication by the observer.
Further, as disclosed in Japanese Patent Publication No. HEI 1-43282 and Japanese Patent Laid-Open No. HEI 1-113717, there have been trials in which a laser light is converted into a plurality of spot lights by a fiber lens, and in which a pattern on end surfaces of a plurality of light guide fibers is utilized to produce a plurality of spot lights, the spot lights are projected to an object, and irregularities of the object are measured on the basis of variation in a distance between the spots.
In an apparatus disclosed in the aforesaid Japanese Patent Laid-Open No. SHO 59-187310, scanning of a spot light has been executed by a scanning mechanism which is arranged on a forward end portion of an interior or inside observing unit. Thus, the apparatus disclosed in the aforesaid Japanese Patent Laid-Open No. SHO 59-187310 has a disadvantage that configuration of the forward end portion of the inside observing unit is enlarged. As a result, in a case, for example, where the unit is applied to an endoscope for medical treatment, a diameter of the forward end portion of the endoscope is enlarged, increasing the fear that pain is given to a patient.
Furthermore, in a method disclosed in Japanese Patent Publication No. HEI 1-43282, a distance between spots cannot be measured so that it is difficult to perform spatial resolution.